docs: def verify_convention_version(self, ds):
          """
          Verify that the version in the Conventions field is correct
          """
          try:
              for convention in getattr(ds, "Conventions", '').replace(' ', '').split(','):
                  if convention == 'ACDD-' + self._cc_spec_version:
                      return ratable_result((2, 2), None, []) # name=None so grouped with Globals
  
              # if no/wrong ACDD convention, return appropriate result
              # Result will have name "Global Attributes" to group with globals
              m = ["Conventions does not contain 'ACDD-{}'".format(self._cc_spec_version)]
              return ratable_result((1, 2), "Global Attributes", m)
          except AttributeError: # NetCDF attribute not found
              m = ["No Conventions attribute present; must contain ACDD-{}".format(self._cc_spec_version)]
              # Result will have name "Global Attributes" to group with globals
              return ratable_result((0, 2), "Global Attributes", m)